1. Field of the Invention
The present invention relates to a method of identifying a signal, such as a source of sound, for example, and a device for implementing the method.
The purpose of a method according to the invention is to identify the source of an unwanted noise (or other signal) in a machine, for example an aircraft, a road vehicle (automobile, truck, coach, etc.), a stationary industrial machine, etc.
2. Description of the Prior Art
A method of identifying a sourse of an unwanted noise without manual intervention, is as yet unknown. At present, in case of an aircraft, unwanted noises are identified either before the aircraft is delivered by the manufacturer or when an unwanted noise appears during the operation of the aircraft by an airline. The expression “unwanted noise” refers to a noise that is perceptible in flight at an abnormal and unacceptable sound level. To identify the noise, a specialist in acoustics and aeronautical engineering is called in to identify the source of the unwanted noise during test flights. Using his knowledge and experience, the expert identifies the sources of unwanted noises that he hears. This “manual” and empirical procedure is effective but costly.
In a field related the present invention, the documents U.S. Pat. No. -4,884,449and U.S. Pat. No.-2001012981, for example, disclose methods based on using a sound recording. These two documents describe the attempt to determine if a part of a machine, for example a bearing, is defective or not. Here it is not a question of identifying the source of an unknown noise but of determining if a noise emitted by a known source includes anomalies or not.
An object of the present invention is therefore to provide a method of identifying a source, in particular a sound source, without the intervention of an acoustics specialist.